Class 12 Chemistry MCQ Chapter 1 Solutions English Medium
Are you searching for AHSEC Class 12 Chemistry MCQ Chapter 1 Solutions English Medium? If yes, then you are in the right place. This article provides a complete collection of Chapter 1 Multiple Choice Questions (MCQs) with accurate answers and explanations for AHSEC Higher Secondary students.
These MCQ solutions are prepared according to the latest AHSEC syllabus and examination pattern. The questions cover all important concepts, definitions, formulas, reactions, and theoretical topics from Chapter 1, helping students strengthen their understanding and improve their examination performance.
Regular practice of these objective questions will help students enhance their accuracy, speed, and confidence for unit tests, school examinations, competitive examinations, and the AHSEC Higher Secondary Final Examination.
All questions and answers are written in simple and easy-to-understand English, making them suitable for quick revision and effective exam preparation. Whether you are revising the chapter or testing your knowledge, these MCQ solutions will serve as a valuable study resource.
Part I
Class 12 Chemistry MCQ Chapter 1 Solutions
VSA & MCQ
I. Very Short Question-Answers (VSA)
Q. What is a solution?
Ans: A solution is a homogeneous mixture of two or more substances.
Q. What is meant by solute?
Ans: The component present in smaller amounts is called solute.
Q. What is solvent?
Ans: The component present in larger amounts is called solvent.
Q. Define molarity.
Ans: Molarity (M) = number of moles of solute/volume of solution in litres.
Q. Define molality.
Ans: Molality (m) = number of moles of solute/mass of solvent in kg.
Q. What is mole fraction?
Ans: Mole fraction = moles of a component/total moles of all components.
Q. What is ppm?
Ans: Parts per million (ppm) = (mass of solute/mass of solution) × 10⁶.
Q. What is Henry’s law?
Ans: It states that solubility of a gas in a liquid is proportional to the pressure of the gas.
Q. Write Henry’s law expression.
Ans: p = kH × x
Q. What is vapour pressure?
Ans: It is the pressure exerted by vapour in equilibrium with its liquid.
Q. State Raoult’s law.
Ans: p₁ = x₁ × p₁⁰
Q. What is relative lowering of vapour pressure?
Ans: (p⁰ − p) / p⁰
Q. What is an ideal solution?
Ans: A solution that obeys Raoult’s law over the entire concentration range.
Q. What is non-ideal solution?
Ans: A solution that does not obey Raoult’s law.
Q. What is azeotrope?
Ans: A mixture of liquids that boils at constant temperature with fixed composition.
Q. Define boiling point elevation.
Ans: Increase in boiling point of solvent due to addition of solute.
Q. Expression for elevation in boiling point.
Ans: ΔTb = Kb × m
Q. Define depression in freezing point.
Ans: Decrease in freezing point of solvent due to solute.
Q. Expression for depression in freezing point.
Ans: ΔTf = Kf × m
Q. What are colligative properties?
Ans: Properties depending only on number of solute particles.
Q. Name four colligative properties.
Ans: Relative lowering of vapour pressure, elevation of boiling point, depression of freezing point, osmotic pressure.
Q. What is osmotic pressure?
Ans: Pressure required to stop osmosis.
Q. Write osmotic pressure equation.
Ans: π = C R T
Q. What is reverse osmosis?
Ans: Flow of solvent from solution to pure solvent under pressure.
Q. What is abnormal molar mass?
Ans: Molar mass obtained due to association or dissociation.
Q. Define degree of dissociation.
Ans: Fraction of molecules that dissociate.
Q. What is isotonic solution?
Ans: Solutions having same osmotic pressure.
Q. What is hypertonic solution?
Ans: Solution with higher osmotic pressure.
II. Multiple Choice Questions (MCQs)
Q. Which of the following is a homogeneous mixture?
(a) Solution
(b) Suspension
(c) Colloid
(d) Emulsion
Ans: (a)
Q. Molarity depends on:
(a) Temperature
(b) Pressure
(c) Volume only
(d) Mass only
Ans: (a)
Q. Molality depends on:
(a) Temperature
(b) Pressure
(c) Mass
(d) Volume
Ans: (c)
Q. Unit of molarity is:
(a) mol kg⁻¹
(b) mol L⁻¹
(c) g L⁻¹
(d) kg mol⁻¹
Ans: (b)
Q. Raoult’s law is applicable to:
(a) Ideal solution
(b) Non-ideal solution
(c) Colloids
(d) Suspensions
Ans: (a)
Q. Vapour pressure of solution is:
(a) Greater than solvent
(b) Equal
(c) Lower
(d) Zero
Ans: (c)
Q. Boiling point increases due to:
(a) Increase in vapour pressure
(b) Decrease in vapour pressure
(c) No change
(d) Increase in temperature
Ans: (b)
Q. Freezing point decreases due to:
(a) Increase in vapour pressure
(b) Decrease in vapour pressure
(c) Increase in solute
(d) Both (b) and (c)
Ans: (d)
Q. Osmotic pressure depends on:
(a) Nature
(b) Number of particles
(c) Volume
(d) Pressure
Ans: (b)
Q. Colligative properties depend on:
(a) Nature
(b) Temperature
(c) Number
(d) Volume
Ans: (c)
Q. Ideal solution shows:
(a) ΔH = 0
(b) ΔV = 0
(c) Both (a) and (b)
(d) None
Ans: (c)
Q. Azeotropes have:
(a) Variable composition
(b) Constant composition
(c) No boiling point
(d) Infinite boiling
Ans: (b)
Q. Henry’s law constant increases with:
(a) Temperature
(b) Pressure
(c) Volume
(d) Mass
Ans: (a)
Q. Assertion: Osmotic pressure is a colligative property.
Reason: It depends on number of solute particles.
(a) Both true, R correct explanation
(b) Both true, R not correct explanation
(c) A true, R false
(d) A false, R true
Ans: (b)
Q. Assertion: Molality is temperature-independent.
Reason: It depends on mass of solvent.
(a) Both true, R correct explanation
(b) Both true, R not correct explanation
(c) A true, R false
(d) A false, R true
Ans: (d)
Q. Assertion: Vapour pressure decreases on adding solute.
Reason: Solute particles occupy surface area.
(a) Both true, R correct explanation
(b) Both true, R not correct explanation
(c) A true, R false
(d) A false, R true
Ans: (c)
Q. Assertion: Ideal solutions obey Raoult’s law.
Reason: Intermolecular forces are equal.
(a) Both true, R correct explanation
(b) Both true, R not correct explanation
(c) A true, R false
(d) A false, R true
Ans: (a)
Q. Assertion: Boiling point increases in solution.
Reason: Vapour pressure decreases.
(a) Both true, R correct explanation
(b) Both true, R not correct explanation
(c) A true, R false
(d) A false, R true
Ans: (b)
Q. Assertion: Freezing point decreases in solution.
Reason: Solute lowers vapour pressure.
(a) Both true, R correct explanation
(b) Both true, R not correct explanation
(c) A true, R false
(d) A false, R true
Ans: (d)
Q. Assertion: Van’t Hoff factor is always 1.
Reason: Solute does not dissociate.
(a) Both true, R correct explanation
(b) Both true, R not correct explanation
(c) A true, R false
(d) A false, R true
Ans: (c)
